Files: da7b20096a9e2da5c16128a768e529a9070114a8 / interface.js
14958 bytesRaw
1 | /** |
2 | * This is the Ethereum interface that is exposed to the WASM instance which |
3 | * enables to interact with the Ethereum Environment |
4 | */ |
5 | const constants = require('./constants.js') |
6 | const Address = require('./address.js') |
7 | const U256 = require('./u256.js') |
8 | |
9 | // The interface exposed to the WebAessembly Core |
10 | module.exports = class Interface { |
11 | constructor (environment) { |
12 | this.environment = environment |
13 | } |
14 | |
15 | get exportTable () { |
16 | let exportMethods = [ |
17 | // include all the public methods according to the Ethereum Environment Interface (EEI) r1 |
18 | 'useGas', |
19 | 'getGasLeft', |
20 | 'getAddress', |
21 | 'getBalance', |
22 | 'getTxOrigin', |
23 | 'getCaller', |
24 | 'getCallValue', |
25 | 'getCallDataSize', |
26 | 'callDataCopy', |
27 | 'getCodeSize', |
28 | 'codeCopy', |
29 | 'getExternalCodeSize', |
30 | 'externalCodeCopy', |
31 | 'getTxGasPrice', |
32 | 'getBlockHash', |
33 | 'getBlockCoinbase', |
34 | 'getBlockTimestamp', |
35 | 'getBlockNumber', |
36 | 'getBlockDifficulty', |
37 | 'getBlockGasLimit', |
38 | 'log', |
39 | 'create', |
40 | 'call', |
41 | 'callCode', |
42 | 'callDelegate', |
43 | 'storageStore', |
44 | 'storageLoad', |
45 | 'return', |
46 | 'selfDestruct' |
47 | ] |
48 | let ret = {} |
49 | exportMethods.forEach((method) => { |
50 | ret[method] = this[method].bind(this) |
51 | }) |
52 | return ret |
53 | } |
54 | |
55 | setModule (mod) { |
56 | this.module = mod |
57 | } |
58 | |
59 | /** |
60 | * Subtracts an amount to the gas counter |
61 | * @param {integer} amount the amount to subtract to the gas counter |
62 | */ |
63 | useGas (amount) { |
64 | if (amount < 0) { |
65 | throw new Error('Negative gas deduction requested') |
66 | } |
67 | |
68 | if (this.environment.gasLimit < amount) { |
69 | throw new Error('Ran out of gas') |
70 | } |
71 | |
72 | this.environment.gasLimit -= amount |
73 | } |
74 | |
75 | /** |
76 | * Returns the current amount of gas |
77 | * @return {integer} |
78 | */ |
79 | getGasLeft () { |
80 | return this.environment.gasLimit |
81 | } |
82 | |
83 | /** |
84 | * Gets address of currently executing account and loads it into memory at |
85 | * the given offset. |
86 | * @param {integer} offset |
87 | */ |
88 | getAddress (offset) { |
89 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.address) |
90 | } |
91 | |
92 | /** |
93 | * Gets balance of the given account and loads it into memory at the given |
94 | * offset. |
95 | * @param {integer} addressOffset the memory offset to laod the address |
96 | * @param {integer} resultOffset |
97 | */ |
98 | getBalance (addressOffset, offset) { |
99 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
100 | // call the parent contract and ask for the balance of one of its child contracts |
101 | const balance = this.environment.parent.environment.getBalance(address) |
102 | this.setMemory(offset, constants.BALANCE_SIZE_BYTES, balance.toBuffer(constants.BALANCE_SIZE_BYTES)) |
103 | } |
104 | |
105 | /** |
106 | * Gets the execution's origination address and loads it into memory at the |
107 | * given offset. This is the sender of original transaction; it is never an |
108 | * account with non-empty associated code. |
109 | * @param {integer} offset |
110 | */ |
111 | getTxOrigin (offset) { |
112 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.origin) |
113 | } |
114 | |
115 | /** |
116 | * Gets caller address and loads it into memory at the given offset. This is |
117 | * the address of the account that is directly responsible for this execution. |
118 | * @param {integer} offset |
119 | */ |
120 | getCaller (offset) { |
121 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.caller) |
122 | } |
123 | |
124 | /** |
125 | * Gets the deposited value by the instruction/transaction responsible for |
126 | * this execution and loads it into memory at the given location. |
127 | * @param {integer} offset |
128 | */ |
129 | getCallValue (offset) { |
130 | this.setMemory(offset, constants.BALANCE_SIZE_BYTES, this.environment.callValue.toBuffer(constants.BALANCE_SIZE_BYTES)) |
131 | } |
132 | |
133 | /** |
134 | * Get size of input data in current environment. This pertains to the input |
135 | * data passed with the message call instruction or transaction. |
136 | * @return {integer} |
137 | */ |
138 | getCallDataSize () { |
139 | return this.environment.callData.length |
140 | } |
141 | |
142 | /** |
143 | * Copys the input data in current environment to memory. This pertains to |
144 | * the input data passed with the message call instruction or transaction. |
145 | * @param {integer} offset the offset in memory to load into |
146 | * @param {integer} dataOffset the offset in the input data |
147 | * @param {integer} length the length of data to copy |
148 | */ |
149 | callDataCopy (offset, dataOffset, length) { |
150 | const callData = this.environment.callData.slice(dataOffset, dataOffset + length) |
151 | this.setMemory(offset, length, callData) |
152 | } |
153 | |
154 | /** |
155 | * Gets the size of code running in current environment. |
156 | * @return {interger} |
157 | */ |
158 | getCodeSize () { |
159 | return this.environment.code.length |
160 | } |
161 | |
162 | /** |
163 | * Copys the code running in current environment to memory. |
164 | * @param {integer} offset the memory offset |
165 | * @param {integer} codeOffset the code offset |
166 | * @param {integer} length the length of code to copy |
167 | */ |
168 | codeCopy (resultOffset, codeOffset, length) { |
169 | const code = new Uint8Array(this.environment.code, codeOffset, length) |
170 | this.setMemory(resultOffset, length, code) |
171 | } |
172 | |
173 | /** |
174 | * Get size of an account’s code. |
175 | * @param {integer} addressOffset the offset in memory to load the address from |
176 | * @return {integer} |
177 | */ |
178 | getExternalCodeSize (addressOffset) { |
179 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
180 | const code = this.environment.getCode(address) |
181 | return code.length |
182 | } |
183 | |
184 | /** |
185 | * Copys the code of an account to memory. |
186 | * @param {integer} addressOffset the memory offset of the address |
187 | * @param {integer} resultOffset the memory offset |
188 | * @param {integer} codeOffset the code offset |
189 | * @param {integer} length the length of code to copy |
190 | */ |
191 | externalCodeCopy (addressOffset, resultOffset, codeOffset, length) { |
192 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
193 | let code = this.environment.getCode(address) |
194 | code = new Uint8Array(code, codeOffset, length) |
195 | this.setMemory(resultOffset, length, code) |
196 | } |
197 | |
198 | /** |
199 | * Gets price of gas in current environment. |
200 | * @return {integer} |
201 | */ |
202 | getTxGasPrice () { |
203 | return this.environment.gasPrice |
204 | } |
205 | |
206 | /** |
207 | * Gets the hash of one of the 256 most recent complete blocks. |
208 | * @param {integer} number which block to load |
209 | * @param {integer} offset the offset to load the hash into |
210 | */ |
211 | getBlockHash (number, offset) { |
212 | const diff = this.environment.number - number |
213 | let hash |
214 | |
215 | if (diff > 256 || diff <= 0) { |
216 | hash = new U256(0) |
217 | } else { |
218 | hash = new U256(this.environment.getBlockHash(number)) |
219 | } |
220 | this.setMemory(offset, 32, hash.toBuffer()) |
221 | } |
222 | |
223 | /** |
224 | * Gets the block’s beneficiary address and loads into memory. |
225 | * @param offset |
226 | */ |
227 | getBlockCoinbase (offset) { |
228 | this.setMemory(offset, constants.ADDRESS_SIZE_BYTES, this.environment.coinbase) |
229 | } |
230 | |
231 | /** |
232 | * Get the block’s timestamp. |
233 | * @return {integer} |
234 | */ |
235 | getBlockTimestamp () { |
236 | return this.environment.timestamp |
237 | } |
238 | |
239 | /** |
240 | * Get the block’s number. |
241 | * @return {integer} |
242 | */ |
243 | getBlockNumber () { |
244 | return this.environment.number |
245 | } |
246 | |
247 | /** |
248 | * Get the block’s difficulty. |
249 | * @return {integer} |
250 | */ |
251 | getBlockDifficulty () { |
252 | return this.environment.difficulty |
253 | } |
254 | |
255 | /** |
256 | * Get the block’s gas limit. |
257 | * @return {integer} |
258 | */ |
259 | getBlockGasLimit () { |
260 | return this.environment.gasLimit |
261 | } |
262 | |
263 | /** |
264 | * Creates a new log in the current environment |
265 | * @param {integer} dataOffset the offset in memory to load the memory |
266 | * @param {integer} length the data length |
267 | * TODO: replace with variadic |
268 | */ |
269 | log (dataOffset, length, topic1, topic2, topic3, topic4, topic5) { |
270 | const data = this.getMemory(dataOffset, length) |
271 | this.environment.logs.push({ |
272 | data: data, |
273 | topics: [topic1, topic2, topic3, topic4, topic5] |
274 | }) |
275 | } |
276 | |
277 | /** |
278 | * Creates a new contract with a given value. |
279 | * @param {integer} valueOffset the offset in memory to the value from |
280 | * @param {integer} dataOffset the offset to load the code for the new contract from |
281 | * @param {integer} length the data length |
282 | */ |
283 | create (valueOffset, dataOffset, length) { |
284 | const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES)) |
285 | const data = this.getMemory(dataOffset, length) |
286 | const result = this.environment.create(value, data) |
287 | return result |
288 | } |
289 | |
290 | /** |
291 | * Sends a message with arbiatary data to a given address path |
292 | * @param {integer} addressOffset the offset to load the address path from |
293 | * @param {integer} valueOffset the offset to load the value from |
294 | * @param {integer} dataOffset the offset to load data from |
295 | * @param {integer} dataLength the length of data |
296 | * @param {integer} resultOffset the offset to store the result data at |
297 | * @param {integer} resultLength |
298 | * @param {integer} gas |
299 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
300 | * TODO: add proper gas counting |
301 | */ |
302 | call (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) { |
303 | if (gas === undefined) { |
304 | gas = this.gasLeft() |
305 | } |
306 | // Load the params from mem |
307 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
308 | const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES)) |
309 | const data = this.getMemory(dataOffset, dataLength) |
310 | // Run the call |
311 | const [result, errorCode] = this.environment.call(gas, address, value, data) |
312 | this.setMemory(resultOffset, resultLength, result) |
313 | return errorCode |
314 | } |
315 | |
316 | /** |
317 | * Message-call into this account with an alternative account’s code. |
318 | * @param {integer} addressOffset the offset to load the address path from |
319 | * @param {integer} valueOffset the offset to load the value from |
320 | * @param {integer} dataOffset the offset to load data from |
321 | * @param {integer} dataLength the length of data |
322 | * @param {integer} resultOffset the offset to store the result data at |
323 | * @param {integer} resultLength |
324 | * @param {integer} gas |
325 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
326 | * TODO: add proper gas counting |
327 | */ |
328 | callCode (gas, addressOffset, valueOffset, dataOffset, dataLength, resultOffset, resultLength) { |
329 | // Load the params from mem |
330 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
331 | const value = new U256(this.getMemory(valueOffset, constants.BALANCE_SIZE_BYTES)) |
332 | const data = this.getMemory(dataOffset, dataLength) |
333 | // Run the call |
334 | const [result, errorCode] = this.environment.callCode(gas, address, value, data) |
335 | this.setMemory(resultOffset, resultLength, result) |
336 | return errorCode |
337 | } |
338 | |
339 | /** |
340 | * Message-call into this account with an alternative account’s code, but |
341 | * persisting the current values for sender and value. |
342 | * @param {integer} gas |
343 | * @param {integer} addressOffset the offset to load the address path from |
344 | * @param {integer} valueOffset the offset to load the value from |
345 | * @param {integer} dataOffset the offset to load data from |
346 | * @param {integer} dataLength the length of data |
347 | * @param {integer} resultOffset the offset to store the result data at |
348 | * @param {integer} resultLength |
349 | * @return {integer} Returns 1 or 0 depending on if the VM trapped on the message or not |
350 | */ |
351 | callDelegate (gas, addressOffset, dataOffset, dataLength, resultOffset, resultLength) { |
352 | const data = this.getMemory(dataOffset, dataLength) |
353 | const address = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
354 | const [result, errorCode] = this.environment.callDelegate(gas, address, data) |
355 | this.setMemory(resultOffset, resultLength, result) |
356 | return errorCode |
357 | } |
358 | |
359 | /** |
360 | * store a value at a given path in long term storage which are both loaded |
361 | * from Memory |
362 | * @param {interger} pathOffest the memory offset to load the the path from |
363 | * @param {interger} valueOffset the memory offset to load the value from |
364 | */ |
365 | storageStore (pathOffset, valueOffset) { |
366 | const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex') |
367 | // copy the value |
368 | const value = this.getMemory(valueOffset, 32).slice(0) |
369 | const oldValue = this.environment.state.get(path) |
370 | const valIsZero = value.every((i) => i === 0) |
371 | |
372 | // write |
373 | if (!valIsZero && !oldValue) { |
374 | this.environment.gasLimit -= 15000 |
375 | } |
376 | |
377 | // delete |
378 | if (valIsZero && oldValue) { |
379 | this.environment.gasRefund += 15000 |
380 | this.environment.state.delete(path) |
381 | } else { |
382 | this.environment.state.set(path, value) |
383 | } |
384 | } |
385 | |
386 | /** |
387 | * reterives a value at a given path in long term storage |
388 | * @param {interger} pathOffest the memory offset to load the the path from |
389 | * @param {interger} resultOffset the memory offset to load the value from |
390 | */ |
391 | storageLoad (pathOffset, resultOffset) { |
392 | const path = new Buffer(this.getMemory(pathOffset, 32)).toString('hex') |
393 | const result = this.environment.state.get(path) |
394 | this.setMemory(resultOffset, 32, result) |
395 | } |
396 | |
397 | /** |
398 | * Halt execution returning output data. |
399 | * @param {integer} offset the offset of the output data. |
400 | * @param {integer} length the length of the output data. |
401 | */ |
402 | return (offset, length) { |
403 | this.environment.returnValue = this.getMemory(offset, length) |
404 | } |
405 | |
406 | /** |
407 | * Halt execution and register account for later deletion giving the remaining |
408 | * balance to an address path |
409 | * @param {integer} offset the offset to load the address from |
410 | */ |
411 | selfDestruct (addressOffset) { |
412 | this.environment.suicideAddress = new Address(this.getMemory(addressOffset, constants.ADDRESS_SIZE_BYTES)) |
413 | } |
414 | |
415 | getMemory (offset, length) { |
416 | return new Uint8Array(this.module.exports.memory, offset, length) |
417 | } |
418 | |
419 | setMemory (offset, length, value) { |
420 | const memory = new Uint8Array(this.module.exports.memory, offset, length) |
421 | memory.set(value) |
422 | } |
423 | } |
424 | |
425 | // |
426 | // Polyfill required unless this is sorted: https://bugs.chromium.org/p/chromium/issues/detail?id=633895 |
427 | // |
428 | // Polyfill from: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_objects/Function/bind |
429 | // |
430 | Function.prototype.bind = function (oThis) { // eslint-disable-line |
431 | if (typeof this !== 'function') { |
432 | // closest thing possible to the ECMAScript 5 |
433 | // internal IsCallable function |
434 | throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable') |
435 | } |
436 | |
437 | var aArgs = Array.prototype.slice.call(arguments, 1) |
438 | var fToBind = this |
439 | var fNOP = function () {} |
440 | var fBound = function () { |
441 | return fToBind.apply(this instanceof fNOP ? this : oThis, |
442 | aArgs.concat(Array.prototype.slice.call(arguments))) |
443 | } |
444 | |
445 | if (this.prototype) { |
446 | // Function.prototype doesn't have a prototype property |
447 | fNOP.prototype = this.prototype |
448 | } |
449 | |
450 | fBound.prototype = new fNOP() // eslint-disable-line new-cap |
451 | |
452 | return fBound |
453 | } |
454 |
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